I've never really understood how どうした works and hope someone can explain or point me towards further reading.
For example, in my textbook, the following question is asked in relation to a short passage:
The passage describes a young man, Sumitomo-kun, who from about the time he entered elementary school attended juku. The passage explains that because his mother felt the schools you attended were important to succeeding in life she sent him from this age despite thinking at some level that it was too early.
The answer to this question seems to be in the following part:
What I don't understand is why the question used どうした. Could it have used 何をした instead?
More broadly, what are the differences between the two questions?